1. Field of the Invention
The present invention relates to a printing apparatus printing a composite image obtained by synthesizing an enlargement portion obtained by enlarging one portion of an original image and a non-enlargement portion, a print data generating apparatus and a print data generating program that generate print data for printing the composite image as above.
2. Description of the Related Art
In a printing system disclosed in Japanese Patent Application Laid-open No. 2008-92393, when a user surrounds, of a sample image printed on an order sheet, a region to be enlarged that is desired to be enlarged by a marker, and checks check columns for designating an enlargement rate and a placement of the region to be enlarged, and then causes a scanner to read the order sheet, in a printing apparatus, an image where only a portion to be enlarged is enlarged on the sample image, namely, a composite image obtained by synthesizing the portion to be enlarged that is enlarged (an enlargement portion) and a portion except the above (non-enlargement portion) is printed.
Further, in a printing system disclosed in Japanese Patent Application Laid-open No. 2001-195213, in a printer driver, thinning-out processing in which data of some pixels are thinned out from image data of an original image at a predetermined thinning-out rate is performed, and thereby print image data whose data amount is smaller than that of the image data of the original image is generated, and the above print image data is transferred to a printer, and thereby printing is performed. Accordingly, when printing is performed at a resolution lower than that of the data of the original image, or the like, the print image data obtained by thinning out data of pixels that are not used for printing from the data of the original image is transferred to the printer, and thus processing can be speeded up.
Here, in the case when by using the printing system in which printing is performed by data obtained by thinning out part of image data of an original image as disclosed in Japanese Patent Application Laid-open No. 2001-195213, a composite image obtained by synthesizing an enlargement portion obtained by enlarging one portion of the original image and a non-enlargement portion is printed as disclosed in Japanese Patent Application Laid-open No. 2008-92393, when in both the enlargement portion and the non-enlargement portion, print image data are generated by thinning out the data of the original image at the same thinning-out rate and the composite image is printed based on the generated print image data, a resolution in the enlargement portion becomes lower than that in the non-enlargement portion because the enlargement portion is enlarged. As a result, in the printed composite image, difference in image quality occurs between the enlargement portion and the non-enlargement portion.